Probiotics using microorganisms have been known to improve the enterobacterial flora of animals, prevent diarrhea, activate immunity, and so on. For example, Patent Document 1 discloses pasteurized ingredients derived from bacterial cells to prevent diarrhea in animals. Also, Patent Document 2 discloses a compound containing one kind of lactic acid bacteria, Lactobacillus. In addition, Patent Document 3 discloses an antimicrobial compound derived from Bacillus subtilis, which is a species of the genus Bacillus. Furthermore, Patent Document 4 discloses microorganisms having ability to colonize on the gastrointestinal tract, which are symbionts including Yeast, Lactobacillus and Bifidobacterium. Furthermore, Patent Document 5 discloses an immunopotentiator including one kind of lactic acid bacteria, such as Lactobacillus. Probiotics disclosed in these patent documents are those using microorganisms proliferative at normal temperatures, but not using any thermophilic microorganism.
Furthermore, the followings are examples of influences of administering microorganisms proliferative at normal temperatures to animals on immune systems and metabolic regulations and the action mechanisms of such influences.
In Non-Patent Document 1, it is reported that Bacillus subtilis increases CCL21 gene expression by symbiosis with the Bacteroides in the appendix of a rabbit. Furthermore, in Non-Patent Document 2, it is reported that Salmonellas known as pathogenic bacteria derived from animals inhibit the expression of chemokines CXCL13 and CCL21, which are chemostatic factors for B cells in the immune system, through sensors, Toll-like receptor 4, in the mucous membrane immune system. Furthermore, Non-Patent Document 3 discloses that the above chemokine CXCL13 and the like play a role in development of lymph nodes in the living body, and Non-Patent Document 4 discloses that they relate to the formation of immune functions in the respiratory system.
In Non-Patent Document 5, furthermore, segmented filamentous bacteria are disclosed as bacteria that regulate the functions of the Peyer's patches, the regulatory site of the immune system in the intestinal tract. Furthermore, in Non-Patent Document 6, an attempt to introduce human's flora is also carried out by introduction of the special bacteria such as those described above into germ-free animals (axenic animals).
On the other hand, Patent Documents 6 to 8 disclose techniques using thermophilic microorganisms. The techniques using thermophilic microorganisms have a great advantage in that, for example, they allow organic waste materials to be recycled and thus formulated for respective applications. Each of the above patent documents discloses promotion of making compost from feces and urine, reduction of smells, and the like when administering Bacillus having chitin degradation ability to farm animals. However, the mechanisms of action of these techniques are not described in detail. In other words, these patent documents do not disclose direct effects of administration of thermophilic microorganism to an animal on a living body, particularly an influence thereof on the immune or endocrine system.
As described above, any of the conventional techniques for regulating the immune system is just something to use only a microorganism proliferative at normal temperatures. In particular, the conventional techniques cannot simultaneously attain advantageous effects of enhancing muscle-building effects, regulating gas metabolism and fat metabolism to reduce in greenhouse gases generated from intestinal contents, and regulating a fat accumulation in the body. Alternatively, the conventional techniques using thermophilic microorganisms declare effects on manure and feed, and environmental improvement effects.